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3 years ago

What is the definition of inverse operation

Mathematics

1 answer:

barxatty [35]3 years ago

3 0

The reverse effect of another operation
ex multiply - division

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Suppose we are interested in analyzing the weights of NFL players. We know that on average, NFL players weigh 247 pounds with a

Diano4ka-milaya [45]

Answer:

a) The standard error would be of 8.58 pounds.

b) The margin of error is 14.11 pounds.

c) The 90% confidence interval for the population mean is between 232.89 pounds and 261.11 pounds

Step-by-step explanation:

a.What is the standard error?

The standard error is

$s = \frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample. So

$s = \frac{47}{\sqrt{30}} = 8.58$

The standard error would be of 8.58 pounds.

b.What is the margin of error at 90% confidence?

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.9}{2} = 0.05$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.05 = 0.95$ , so $z = 1.645$

Now, find the margin of error M as such

$M = z*s = 1.645*8.58 = 14.11$

The margin of error is 14.11 pounds.

c. Using my sample of 30, what would be the 90% confidence interval for the population mean?

Lower bound: Sample mean subtracted by the margin of error.

247 - 14.11 = 232.89 pounds

Upper bound

247 + 14.11 = 261.11 pounds

The 90% confidence interval for the population mean is between 232.89 pounds and 261.11 pounds

4 0

3 years ago

The temperature in Anchorage, Alaska at 6 a.m. was 2°C. If the temperature drops 2 degrees each hour, what is the temperature in

Alchen [17]

Answer:

-14°C

Step-by-step explanation:

6 + 8 = 14

So in 24 hour time that would be 2pm

From 6am to 2pm is 8 hours

If the degrees is going down by 2 you would times the 8 by 2 because it is doubled

That = 16

Then you'll minus 16°C from the 2°C

2°C - 16°C

= -14°C

4 0

3 years ago

Help i will give brainliest

Kamila [148]

Answer:

Step-by-step explanation:

Area of circle = 56 cm²

πr² = 56

3.14r² = 56

r²=56/3.14

r²= 17.83

r = √17.83

r = 4.22 cm

The diameter of the circle = diagonal of the square

Diagonal of the square = 2 * 4.22 = 8.44 cm

x² + x² = 8.44²

2x² = 71.2336

x² = 71.2336/2

x² = 35.6168

x = 5.967 cm

5 0

3 years ago

A 20% acid solution is mixed with 20 liters of a 45% acid solution. How much of a 30% acid solution will result?

vaieri [72.5K]

Answer:

50 liters

Step-by-step explanation:

If x is the volume of 20% acid, then:

x (0.20) + 20 (0.45) = (x + 20) (0.30)

0.2x + 9 = 0.3x + 6

3 = 0.1x

x = 30

30 liters of 20% acid are needed, so there will be a total of 50 liters of 30% acid.

6 0

3 years ago

A first play of football game resulted in a loss of 12.5 yards. Then a penalty resulted in another loss of 5 yards. What is the

lions [1.4K]

The total loss is 17.5 yards.

8 0

3 years ago